Monoazo dyestuffs soluble in water



Patented June 27, 1939 PATENT OFFICE MONOAZO DYES'I UFFS SOLUBLE IN WATER Erich Fischer, Bad Soden in Taunus, and Richard Huss and Walter Gmelin, Frankfort-on-the- Main-Hochst, Germany, assignors to General Aniline Works, Inc.,

New York, N. Y., a corporatio'n of Delaware No Drawing. Application April 2, 1937, Serial No. 134,678. In Germany April 11, 1936 Claims.

The present invention relates to monoazodyestuffs soluble in'water; more particularly it relates to compounds of the following general formula:

HO s 3 sulfonic acid or its N-alkyl or N-aryl derivatives.

The dyestuffs obtained are especially adapted for dyeing leather various brown tints. They are distinguished by a good levelling power and pos-v sees the valuable property of penetrating deeply into the leather or of through-dyeing it.

The following examples serve to'illustrate the invention, but they are not intended to limit it thereto; the parts are by weight, unless otherwise stated:

(1) 18.7 parts of 4-amino-benzyl-sulfonic acid (molecular weight 187) are dissolved in 200 parts by volume of water with 5.5 parts of calcined sodium carbonate. This solution is poured into parts by volume of hydrochloric acid of 20 B. and, in the presence of ice, diazotized with 6.9 parts of sodium nitrite. The'diazo solution obtained is then-caused to run,- at 0 (3., into an aqueous solution of 27.5 parts of sodium Z-amino- 8-naphthol-6-sulfonate (molecular weight 261) and 20 parts of calcined sodium carbonate. When the coupling is complete the dyestuff is isolated in the usual manner and dried. It is a brown powder which dissolves in water to a bluish red-brown solution and is, for instance, suitable for dyeing chrome-tanned calf. The dyestuff has the following formula: I

HOEIS/ above dyestuff for one hour at C. After addition of formic acid, the leather is greased in a fresh bath and finished as usual. The cross-section of the leather is well through-dyed and the leather may well be bufied without changing its tint.

(2) 18.7 parts of 4-amino-benzyl-sulfonic acid are diazotized in the manner indicated in Example 1 and combined, in the presence of a sodium carbonate solution in excess, with a solution of 29 parts of sodium 2-methylamino-8-naphthol-6- sulfonate (molecular weight 275) at 0 C. When the coupling is complete the dyestuff is isolated and dried. It is a brown powder which dissolves in water to a brown solution. The product is especially suitable for dyeing leather.

Chrome-tanned goatskin is de-acidified as usual and dyed with 2% of the above dyestuff. The leather is well through-dyed.

If the sodium 2-methylamino-8-naphthol-6- sulfonate used in this example is exchanged for the equivalent proportion of sodium 2-ethylamino-8-naphthol-6-sulfonate, a dyestuff is obtained which has a tint and properties Very sim-.

ilar to those of the above dyestufi".

When using as diazo compound, instead of 4-amino-benzyl-sulfonic acid, 3-amino-benzylsulionic'acid or 2-amino-benzyl-sulfonic acid, dyestuffs are obtained which through-dye the leather in a similar manner.

(3) 23.9 parts of sodium 3-amino-4-methoxy benzyl-sulfonate are dissolved in 200 parts by volume of water, 25 parts by volume of hydro-. chloric acid of 20 B. are added thereto and the whole is diazotized, at 0 C., with 6.9 parts of sodium nitrite. The diazo solution obtained is combined at 0 C. with 35 parts of sodium 2-phenylamino-B-naphthol-G-sulfonate, in the presence of a sodium' carbonate solution in excess. The dyestuiT obtained is isolated in the usual manner and dried. It is a violet-black powder whichdissolves in water to a brown-violet solution. The dyestuff dyes leather violet brown tints, for instance, asfollows:

East Indian kips are dyed afterdrumming with 100 grams of the dyestuff for 1 dozen kips. After a 50 minutes drumming, 50 grams of formic acid of strength are added to the bath. The dyestuff penetrates deeply into the leather which is finished as usual; After drying, the leather may be buffed and used for velvet effects.

If the 3-amino-4-methoxy-benzyl-sulfonic acid used in/this. example is exchanged forthe 3- amino 4-ethoxy-benzy1-sulfonic acid, there are obtained on leather dyeings which possess very similar properties.

(4) 28.1 parts of 3 amino 1.4 di -(sulfo methyD-benzene (molecular weight 281) are diazotized as usual with 6.9 parts of sodium nitrite, in the presence of ice and hydrochloric acid in excess. The diazo solution obtained is combined at C. with 35 parts of sodium 2- phenylamino 8 naphthol 6 sulfonate in the presence of sodium carbonate in excess. When the coupling is complete, the dyestuff is separated and dried. It is characterized by the following formula:

CHzSOaH (SH-2803B HOaS and is a black-brown powder which dissolves in Water to a reddish-brown solution.

According to the dyeing process indicated in Example 1, this dyestuif yields on leather dyeings which are penetrated deeply into the leather.

A dyestuff of similar properties is obtained if the sodium-2-phenylamino-8-naphthol 6 sulfonate is replaced by the sodium 2-(4-methoxyphenylamino) -8-naphthol-6-sulfonate.

20.1 parts of 3-amino-4-methyl-benzylsulfonic acid (molecular weight 201) are diazotized as usual at 0 C.-5 C. with 6.9 parts of sodium nitrite in the presence of hydrochloric acid in excess. The diazo solution obtained is then caused to run at 0 C. into an aqueous solution of 27.5 parts of sodium 2-amino-8-naphtholfi-sulfonate in the presence of sodium carbonate in excess. When the coupling is complete the dyestufi is separated in the usual manner and dried. It is a black-brown powder which dissolves in water to a red-brown solution and which penetrates deeply into chrome-tanned goatskin, for instance according to the dyeing process indicated in Example 2.

A deeper brown which likewise pentrates deeply into the leather is obtained, if, instead of the diazo component used in this example there is used 3-amino 6 acetylamino benzylsulfonic acid.

(6) 23.9 parts of sodium 3-amino-4-methoxybenzyl-sulfonate are diazotized, as indicated in Example 3. An aqueous solution of 28 parts of sodium 2-amino-8-naphthol 6 sulfonate rendered distinctly acid to litmus is then caused to run, at 0 C., while well stirring, into the diazo solution obtained. By addition of sodium acetate, the formation of the dyestuff is accelerated. When the coupling is complete the dyestufi is separated in the usual manner and dried.

According to the dyeing process indicated in Example 1, this dyestuff dyes leather red-brown tints, while penetrating deeply into the leather, which may well be buffed.

(7) 22.15 parts of 3-chloro-4-amino-benzylsulfonic acid are dissolved in 100 parts by volume of water with 5.5 parts of anhydrous sodium carbonate. 25 parts by volume of hydrochloric acid of 20 B are added to this solution and the whole is diazotized at 0 C. with 6.9 parts of sodium nitrite. The diazo solution is then introduced, at 0 C., while stirring, into an aqueous solution of 27.5 parts of sodium 2-amino-8- naphthol-S-sulfonate (molecular weight 261) and 25 parts of anhydrous sodium carbonate. The coupling is immediately complete. The dyestuff is separated and dried. It is a dark brown powder which dissolves in water to a red-brown solution and is, for instance, suitable for dyeing chrome-tanned calf. According to the dyeing process indicated in Example 1, a leather is obtained which shows a red-brown coloration 0n the surface as well as in the section.

If the 3-chloro-4-amino-benzyl-sulfonic acid is replaced by the 3-bromo-4-amino-benzyl-sulfonic acid, a product is obtained which has properties very similar to those of the above dyestuff.

(8) 26.7 parts of 4-amino-3-sulfobenzyl-sul fonic acid are diazotized in the usual manner with 6.9 parts of sodium nitrite in the presence of hydrochloric acid in excess. The diazo solution obtained is combined at 0 C. with 35 parts of sodium Z-phenylamino-8-naphthol-6-sulfonate in the presence of sodium carbonate in excess. When the coupling is complete the dyestuff is separated and dried. It is a black-brown powder which dissolves in water to a brown solution. According to the dyeing process indicated in Example 3, a brown leather is obtained which may Well be buffed and used for velvet effects.

We claim:

1. The monoazo-dyestuffs soluble in water corresponding with the following general formula:

HOaS

responding with the following general formula:

Hons-H2O nols wherein X stands for a member of the group consisting of hydrogen, alkyl and a radical of the benzene series, being brown powders, penetrating deeply into the leather and yielding brown tints of good evenness.

3. The monoazo-dyestufi soluble in water corresponding with the following formula:

being a brown powder, penetrating deeply into the leather and yielding brown tints of good evenness.

4. The monoazo-dyestuff soluble in water corresponding with the following formula:

Hoes

NH-CH:

being a brown powder, penetrating deeply into the leather and yielding brown tints of good evenness.

5. The monoazo-dyestuff soluble in water corresponding with the following formula:

Hms/

ERICH FISCHER. RICHARD HUSS. WALTER GMELIN. 

